You MUST have at least 3 Intelligence AND Faith for him to sell / trade with you (Not boostable).You can trade boss souls with him for Boss Soul Weapons.The mummy aggro range is quite small, and if you carefully walk out from the bonfire while hugging the cell bars, you can talk to Straid without drawing any attention. You'll need to kill them, and Straid is leaning against the wall just to the right as you leave the jail cell. If you return to this bonfire at a later time, the mummies will respawn. There is a bonfire right behind Straid, which is accessible once you free him.Straid of Olaphis is an NPC in Dark Souls 2
